Method for deducting gamma energy spectrum full spectrum background by utilizing successive approximation SNIP (selective nonip) calculation
Method for deducting gamma energy spectrum full spectrum background by utilizing successive approximation SNIP (selective nonip) calculation
 CN 107,219,547 B
 Filed: 05/26/2017
 Issued: 12/29/2020
 Est. Priority Date: 05/26/2017
 Status: Active Grant
First Claim
1. The method for deducting the full spectrum background of the gamma energy spectrum by utilizing successive approximation SNIP (selective nondestructive IP) calculation is characterized by being applied to nondestructive testing;
 further comprising the steps of;
S1、
B^{(n)}representing the background area at the time of background subtraction for the nth time, and setting an initial value B^{(0)}1, n is 0, then B is calculated according to the following procedure^{(n)}：
S2, LLS (logopen) transformation is carried out on the data of the gamma energy spectrum;
z_{i}for the ith trace spectral data, y, after LLS transformation_{i}The ith channel of spectral data before transformation;
s3, constructing a vector r with the size equivalent to the energy spectrum length, and enabling r_{i}＝
t*FWHM_{i}Wherein r is_{i}Represents the width of the ith energy peak, t is a constant representing the relationship between full peak width and full width at half maximum, and FWHM is the full width at half maximum of the peak;
s4, setting the parameter m of the filter window as max { r_{i}}；
S5, calculatingWherein p is ∈
[1, m ]]If p is less than or equal to r_{i}，
If p >
r_{i}，
Representing the ith trace of spectral data after the pth transformation in step 2;
s6, carrying out reverse LLS transformation;
y is_{i}＝
(exp(exp(z_{i})1)1)^{2}1, obtaining a count for each lane;
s7, regarding the background deducted for the first time in the step S6 as a new energy spectrum, repeating the steps S1 to S6 to execute background deduction on the basis of the new energy spectrum until the relative error of the background areas obtained in the previous and subsequent times is satisfiedUntil now.
Chinese PRB Reexamination
Abstract
The invention discloses a method for deducting the full spectrum background of a gamma energy spectrum in nondestructive testing, which can solve the problem that the existing SNIP algorithm has too high dependence on parameters, peak searching and peak regions; the method for deducting the full spectrum background of the gamma energy spectrum in the nondestructive detection improves the selfadaptive peak area width by using the filtering window, improves the background deduction precision by utilizing successive approximation, lays a foundation for accurate analysis of the gamma energy spectrum, and directly calculates the deducted background as a new energy spectrum after the first calculation; the termination condition of iteration is not a fixed step number, and is set until the relative error of background areas obtained twice before and after the condition is metUntil now. Therefore, the method for deducting the full spectrum background of the gamma energy spectrum in the nondestructive testing avoids manual parameter selection, can greatly improve the accuracy of background deduction, does not influence the execution speed of an SNIP algorithm, and has high operation efficiency.
2 Claims

1. The method for deducting the full spectrum background of the gamma energy spectrum by utilizing successive approximation SNIP (selective nondestructive IP) calculation is characterized by being applied to nondestructive testing;
 further comprising the steps of;
S1、
B^{(n)}representing the background area at the time of background subtraction for the nth time, and setting an initial value B^{(0)}1, n is 0, then B is calculated according to the following procedure^{(n)}：S2, LLS (logopen) transformation is carried out on the data of the gamma energy spectrum;
z_{i}for the ith trace spectral data, y, after LLS transformation_{i}The ith channel of spectral data before transformation;s3, constructing a vector r with the size equivalent to the energy spectrum length, and enabling r_{i}＝
t*FWHM_{i}Wherein r is_{i}Represents the width of the ith energy peak, t is a constant representing the relationship between full peak width and full width at half maximum, and FWHM is the full width at half maximum of the peak;s4, setting the parameter m of the filter window as max { r_{i}}； S5, calculatingWherein p is ∈
[1, m ]]If p is less than or equal to r_{i}，
If p >
r_{i}，
Representing the ith trace of spectral data after the pth transformation in step 2;s6, carrying out reverse LLS transformation;
y is_{i}＝
(exp(exp(z_{i})1)1)^{2}1, obtaining a count for each lane;s7, regarding the background deducted for the first time in the step S6 as a new energy spectrum, repeating the steps S1 to S6 to execute background deduction on the basis of the new energy spectrum until the relative error of the background areas obtained in the previous and subsequent times is satisfiedUntil now.
 further comprising the steps of;

2. The method for deducting a full spectrum background of a gamma energy spectrum by utilizing successive approximation SNIP calculation according to claim 1, wherein;
 each calculation is performed with the value of t taken to be 1 in step S3.
Specification(s)